/*
 *  Javascript porting of Markus Kuhn's wcwidth() implementation
 *
 *  The following explanation comes from the original C implementation:
 *
 *  This is an implementation of wcwidth() and wcswidth() (defined in
 *  IEEE Std 1002.1-2001) for Unicode.
 *
 *  http://www.opengroup.org/onlinepubs/007904975/functions/wcwidth.html
 *  http://www.opengroup.org/onlinepubs/007904975/functions/wcswidth.html
 *
 *  In fixed-width output devices, Latin characters all occupy a single
 *  "cell" position of equal width, whereas ideographic CJK characters
 *  occupy two such cells. Interoperability between terminal-line
 *  applications and (teletype-style) character terminals using the
 *  UTF-8 encoding requires agreement on which character should advance
 *  the cursor by how many cell positions. No established formal
 *  standards exist at present on which Unicode character shall occupy
 *  how many cell positions on character terminals. These routines are
 *  a first attempt of defining such behavior based on simple rules
 *  applied to data provided by the Unicode Consortium.
 *
 *  For some graphical characters, the Unicode standard explicitly
 *  defines a character-cell width via the definition of the East Asian
 *  FullWidth (F), Wide (W), Half-width (H), and Narrow (Na) classes.
 *  In all these cases, there is no ambiguity about which width a
 *  terminal shall use. For characters in the East Asian Ambiguous (A)
 *  class, the width choice depends purely on a preference of backward
 *  compatibility with either historic CJK or Western practice.
 *  Choosing single-width for these characters is easy to justify as
 *  the appropriate long-term solution, as the CJK practice of
 *  displaying these characters as double-width comes from historic
 *  implementation simplicity (8-bit encoded characters were displayed
 *  single-width and 16-bit ones double-width, even for Greek,
 *  Cyrillic, etc.) and not any typographic considerations.
 *
 *  Much less clear is the choice of width for the Not East Asian
 *  (Neutral) class. Existing practice does not dictate a width for any
 *  of these characters. It would nevertheless make sense
 *  typographically to allocate two character cells to characters such
 *  as for instance EM SPACE or VOLUME INTEGRAL, which cannot be
 *  represented adequately with a single-width glyph. The following
 *  routines at present merely assign a single-cell width to all
 *  neutral characters, in the interest of simplicity. This is not
 *  entirely satisfactory and should be reconsidered before
 *  establishing a formal standard in this area. At the moment, the
 *  decision which Not East Asian (Neutral) characters should be
 *  represented by double-width glyphs cannot yet be answered by
 *  applying a simple rule from the Unicode database content. Setting
 *  up a proper standard for the behavior of UTF-8 character terminals
 *  will require a careful analysis not only of each Unicode character,
 *  but also of each presentation form, something the author of these
 *  routines has avoided to do so far.
 *
 *  http://www.unicode.org/unicode/reports/tr11/
 *
 *  Markus Kuhn -- 2007-05-26 (Unicode 5.0)
 *
 *  Permission to use, copy, modify, and distribute this software
 *  for any purpose and without fee is hereby granted. The author
 *  disclaims all warranties with regard to this software.
 *
 *  Latest version: http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
 *
 * wcwidth.js: JavaScript Portng of Markus Kuhn's wcwidth() Implementation
 * =======================================================================
 *
 * Copyright (C) 2012 by Jun Woong.
 *
 * This package is a JavaScript porting of Markus Kuhn's wcwidth()
 * implementation distributed on http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR
 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 */


// The following two functions define the column width of an ISO 10646 character as follows:
//
//    - The null character (U+0000) has a column width of 0.
//    - Other C0/C1 control characters and DEL will lead to a return value of -1.
//    - Non-spacing and enclosing combining characters (general category code Mn or Me in the
//      Unicode database) have a column width of 0.
//    - SOFT HYPHEN (U+00AD) has a column width of 1.
//    - Other format characters (general category code Cf in the Unicode database) and ZERO WIDTH
//      SPACE (U+200B) have a column width of 0.
//    - Hangul Jamo medial vowels and final consonants (U+1160-U+11FF) have a column width of 0.
//    - Spacing characters in the East Asian Wide (W) or East Asian Full-width (F) category as
//      defined in Unicode Technical Report #11 have a column width of 2.
//    - All remaining characters (including all printable ISO 8859-1 and WGL4 characters, Unicode
//      control characters, etc.) have a column width of 1.
//
// This implementation assumes that characters are encoded in ISO 10646.
//

(function() {
    // sorted list of non-overlapping intervals of non-spacing characters
    // generated by "uniset +cat=Me +cat=Mn +cat=Cf -00AD +1160-11FF +200B c"
    var combining = [
        [ 0x0300, 0x036F ], [ 0x0483, 0x0486 ], [ 0x0488, 0x0489 ],
        [ 0x0591, 0x05BD ], [ 0x05BF, 0x05BF ], [ 0x05C1, 0x05C2 ],
        [ 0x05C4, 0x05C5 ], [ 0x05C7, 0x05C7 ], [ 0x0600, 0x0603 ],
        [ 0x0610, 0x0615 ], [ 0x064B, 0x065E ], [ 0x0670, 0x0670 ],
        [ 0x06D6, 0x06E4 ], [ 0x06E7, 0x06E8 ], [ 0x06EA, 0x06ED ],
        [ 0x070F, 0x070F ], [ 0x0711, 0x0711 ], [ 0x0730, 0x074A ],
        [ 0x07A6, 0x07B0 ], [ 0x07EB, 0x07F3 ], [ 0x0901, 0x0902 ],
        [ 0x093C, 0x093C ], [ 0x0941, 0x0948 ], [ 0x094D, 0x094D ],
        [ 0x0951, 0x0954 ], [ 0x0962, 0x0963 ], [ 0x0981, 0x0981 ],
        [ 0x09BC, 0x09BC ], [ 0x09C1, 0x09C4 ], [ 0x09CD, 0x09CD ],
        [ 0x09E2, 0x09E3 ], [ 0x0A01, 0x0A02 ], [ 0x0A3C, 0x0A3C ],
        [ 0x0A41, 0x0A42 ], [ 0x0A47, 0x0A48 ], [ 0x0A4B, 0x0A4D ],
        [ 0x0A70, 0x0A71 ], [ 0x0A81, 0x0A82 ], [ 0x0ABC, 0x0ABC ],
        [ 0x0AC1, 0x0AC5 ], [ 0x0AC7, 0x0AC8 ], [ 0x0ACD, 0x0ACD ],
        [ 0x0AE2, 0x0AE3 ], [ 0x0B01, 0x0B01 ], [ 0x0B3C, 0x0B3C ],
        [ 0x0B3F, 0x0B3F ], [ 0x0B41, 0x0B43 ], [ 0x0B4D, 0x0B4D ],
        [ 0x0B56, 0x0B56 ], [ 0x0B82, 0x0B82 ], [ 0x0BC0, 0x0BC0 ],
        [ 0x0BCD, 0x0BCD ], [ 0x0C3E, 0x0C40 ], [ 0x0C46, 0x0C48 ],
        [ 0x0C4A, 0x0C4D ], [ 0x0C55, 0x0C56 ], [ 0x0CBC, 0x0CBC ],
        [ 0x0CBF, 0x0CBF ], [ 0x0CC6, 0x0CC6 ], [ 0x0CCC, 0x0CCD ],
        [ 0x0CE2, 0x0CE3 ], [ 0x0D41, 0x0D43 ], [ 0x0D4D, 0x0D4D ],
        [ 0x0DCA, 0x0DCA ], [ 0x0DD2, 0x0DD4 ], [ 0x0DD6, 0x0DD6 ],
        [ 0x0E31, 0x0E31 ], [ 0x0E34, 0x0E3A ], [ 0x0E47, 0x0E4E ],
        [ 0x0EB1, 0x0EB1 ], [ 0x0EB4, 0x0EB9 ], [ 0x0EBB, 0x0EBC ],
        [ 0x0EC8, 0x0ECD ], [ 0x0F18, 0x0F19 ], [ 0x0F35, 0x0F35 ],
        [ 0x0F37, 0x0F37 ], [ 0x0F39, 0x0F39 ], [ 0x0F71, 0x0F7E ],
        [ 0x0F80, 0x0F84 ], [ 0x0F86, 0x0F87 ], [ 0x0F90, 0x0F97 ],
        [ 0x0F99, 0x0FBC ], [ 0x0FC6, 0x0FC6 ], [ 0x102D, 0x1030 ],
        [ 0x1032, 0x1032 ], [ 0x1036, 0x1037 ], [ 0x1039, 0x1039 ],
        [ 0x1058, 0x1059 ], [ 0x1160, 0x11FF ], [ 0x135F, 0x135F ],
        [ 0x1712, 0x1714 ], [ 0x1732, 0x1734 ], [ 0x1752, 0x1753 ],
        [ 0x1772, 0x1773 ], [ 0x17B4, 0x17B5 ], [ 0x17B7, 0x17BD ],
        [ 0x17C6, 0x17C6 ], [ 0x17C9, 0x17D3 ], [ 0x17DD, 0x17DD ],
        [ 0x180B, 0x180D ], [ 0x18A9, 0x18A9 ], [ 0x1920, 0x1922 ],
        [ 0x1927, 0x1928 ], [ 0x1932, 0x1932 ], [ 0x1939, 0x193B ],
        [ 0x1A17, 0x1A18 ], [ 0x1B00, 0x1B03 ], [ 0x1B34, 0x1B34 ],
        [ 0x1B36, 0x1B3A ], [ 0x1B3C, 0x1B3C ], [ 0x1B42, 0x1B42 ],
        [ 0x1B6B, 0x1B73 ], [ 0x1DC0, 0x1DCA ], [ 0x1DFE, 0x1DFF ],
        [ 0x200B, 0x200F ], [ 0x202A, 0x202E ], [ 0x2060, 0x2063 ],
        [ 0x206A, 0x206F ], [ 0x20D0, 0x20EF ], [ 0x302A, 0x302F ],
        [ 0x3099, 0x309A ], [ 0xA806, 0xA806 ], [ 0xA80B, 0xA80B ],
        [ 0xA825, 0xA826 ], [ 0xFB1E, 0xFB1E ], [ 0xFE00, 0xFE0F ],
        [ 0xFE20, 0xFE23 ], [ 0xFEFF, 0xFEFF ], [ 0xFFF9, 0xFFFB ],
        [ 0x10A01, 0x10A03 ], [ 0x10A05, 0x10A06 ], [ 0x10A0C, 0x10A0F ],
        [ 0x10A38, 0x10A3A ], [ 0x10A3F, 0x10A3F ], [ 0x1D167, 0x1D169 ],
        [ 0x1D173, 0x1D182 ], [ 0x1D185, 0x1D18B ], [ 0x1D1AA, 0x1D1AD ],
        [ 0x1D242, 0x1D244 ], [ 0xE0001, 0xE0001 ], [ 0xE0020, 0xE007F ],
        [ 0xE0100, 0xE01EF ]
    ];

    // auxiliary function for binary search in interval table
    var bisearch = function(ucs) {
        var min = 0,
            max = combining.length-1;
        var mid;

        if (ucs < combining[0][0] || ucs > combining[max][1])
            return false;
        while (max >= min) {
            mid = Math.floor((min + max) / 2);
            if (ucs > combining[mid][1])
                min = mid + 1;
            else if (ucs < combining[mid][0])
                max = mid - 1;
            else
                return true;
        }

       return false;
    }

    option = {
        nul:     0,
        control: -1
    };

    // ucs = 'character' or charCode
    return wcwidth = function (ucs) {
        if (typeof ucs == "string")
            ucs = ucs.charCodeAt(0);

        // test for 8-bit control characters
        if (ucs === 0)
            return option.nul;
        if (ucs < 32 || (ucs >= 0x7f && ucs < 0xa0))
            return option.control;

        // binary search in table of non-spacing characters
        if (bisearch(ucs))
            return 0;

        // if we arrive here, ucs is not a combining or C0/C1 control character
        return 1 +
            (ucs >= 0x1100 &&
             (ucs <= 0x115f ||                       // Hangul Jamo init. consonants
              ucs == 0x2329 || ucs == 0x232a ||
              (ucs >= 0x2e80 && ucs <= 0xa4cf &&
               ucs != 0x303f) ||                     // CJK ... Yi
              (ucs >= 0xac00 && ucs <= 0xd7a3) ||    // Hangul Syllables
              (ucs >= 0xf900 && ucs <= 0xfaff) ||    // CJK Compatibility Ideographs
              (ucs >= 0xfe10 && ucs <= 0xfe19) ||    // Vertical forms
              (ucs >= 0xfe30 && ucs <= 0xfe6f) ||    // CJK Compatibility Forms
              (ucs >= 0xff00 && ucs <= 0xff60) ||    // Fullwidth Forms
              (ucs >= 0xffe0 && ucs <= 0xffe6) ||
              (ucs >= 0x20000 && ucs <= 0x2fffd) ||
              (ucs >= 0x30000 && ucs <= 0x3fffd)));
    };
})();
